Regarding an assembled battery provided with a plurality of single batteries, technologies to perform a capacity adjustment of the plurality of single batteries constructing the assembled battery are generally known. For example, Patent document 1 proposes a technology for detecting that the assembled battery is in a state substantially corresponding to an abnormal state when a time interval, during which a capacity adjustment is executed, becomes less than or equal to a predetermined threshold value.
However, in the above-mentioned prior art, in order to detect such an abnormal state of the assembled battery, the time interval, during which the capacity adjustment is executed, has to become less than or equal to the predetermined threshold value. This leads to the problem of a long time needed to detect that the assembled battery is in a state substantially corresponding to an abnormal state. Also, this leads to another problem that it is possible to detect the assembled battery being in a state substantially corresponding to an abnormal state, but it is impossible to predict time when the assembled battery becomes an abnormal state.
A task to be solved by the invention is to appropriately predict time when an assembled battery provided with a plurality of single batteries becomes an abnormal state.